Data base Search System

Sadtler offer nearly 200 000 digital infrared reference spectra in over fifty different collections and also publish handbooks and guides which cover the areas mentioned above. The Sadtler computer-based search system" and the other systems available from manufacturers such as Nicolet, Perkin Elmer, Bio Rad, etc., are all relatively easy to use. Sadtler also offer a computer-based system which contains both IR and NMR data, etc. Library search software packages, such as the Sadtler IR SearchMaster Software, the Spectrafile IR Search Software or the Spectra Calc Search Software, are frequently offered by FT-IR manufacturers in addition to specific search software formatted to operate with their particular data-stations/instruments/computer systems. Some of these search facilities may also cover a number of libraries not only of different suppliers but also of other techniques such as UV, NMR, MS etc. Obviously, such search software packages are dependent not only on the instrument but also on the user s interests. It should be home in mind that the information retrieved from some search software may not cover certain aspects which may normally be available from the particular Sadtler library being searched, such as physical properties, molecular structure. Chemical Abstracts Service (CAS) Registry Number, common impurities, etc. 

The earliest system which allowed substructure searching involving chemical connectivity input and structure display, was the National Institutes of Health/ Environmental Protection Agency Chemical Information System, the NIH/EPA CIS 14). Its Structure and Nomenclature Search System (SANSS) eventually allowed access to a large range of public data bases. The system allowed access from teletype terminals and was not graphics-based. 

In searching for data on a particular system, a computerized search of Chemical Ah.stract.s, Tngineering Index, and National Technical Information Service (NTIS) data bases should seriously be considered. Although the NTIS computer contains only information published after 1970, one normally can assume that most pre-1970 pubhcations of merit hkely will be referenced in the bibhographies of current articles on the subject. 

Today, analytical evaluation is done on a large scale in a computerized way by means of data bases and expert systems (Sect. 8.3.6). In particular, a library search is a useful tool to identify pure compounds, confirm them and characterize constituents in mixtures. Additionally, unknown new substances may be classified by similarity analysis (Zupan [1986], Hippe [1991], Warr [1993], Hobert [1995]). The library search has its main application in such fields where a large number of components has to be related with large sets of data such as environmental and toxicological analysis (Scott [1995], Pellizarri et al. [1985]). 

Computerized data-base versions of RTECS give the capability of extracting substance lists by "Classification Codes." For example, one might ask the system to search for all compounds with classification Code of TUMORIGEN. How many users will have read the user s guide carefully enough to know that this means only that these compounds may have been reviewed by IARC or NTP but NOT that they have been indicted as tumorigenic ... 

In the last decade, for many toxicologists the on-line literature search has changed from an occasional, sporadic activity to a semicontinuous need. Usually, nontoxicology-related search capabilities are already in place in many companies. Therefore, all that is needed is to expand the information source to include some of the data bases that cover the types of toxicology information one desires. However, if no capabilities exist within an organization, one can approach a university, consultant, or a private contract laboratory and utilize their on-line system at a reasonable rate. It is even possible to access most of these sources from home using a personal computer. The major available on-line data bases are described in the following. 

A second disk in the series (CHEM Data) contains comprehensive information from the CHEMINFO, Registry of Toxic Effects of Chemical Substances (RTECS), and Chemical Evaluation Search and Retrieval System (CESARS) data bases, as well as recommendations on Transport of Dangerous Goods (TDG)/Hazardous Materials (49CFR). 

The NIH/EPA CIS consists of a collection of chemical data bases together with a battery of computer programs for interactive searching through these disk-stored data bases. In addition the CIS has a data referral capability as well as a data analysis software system. It can be thought of then, as having four main areas ... 

The data base that is used in the CNMR search system consists currently of 4,100 CNMR spectra (3). As in the case of the MSSS, every compound has a CAS registry number, and all exact duplicate spectra have been removed from the file. A specific compound may still appear in this file more than once, however, because its CNMR spectrum may have been recorded in different solvents. The CNMR file is still small but is growing at a fairly steady rate and should benefit considerably from recent international agreements to the effect that all major compilations of CNMR data will, in the future, be pooled. 

F. X-ray Powder Difi action Search System. Compounds that fail to crystallize may still be examined by X-ray diffraction, because non-crystalline materials, as powders, give characteristic diffraction patterns. A collection of powder diffraction patterns proves to be a very effective means by which to identify materials and indeed, one of the very earliest search systems in chemical analysis was based upon such data by Hanawalt (21) over forty years ago. The importance of these data in TSCA can be seen by examining the TSCA Inventory regulations for treatment of confidential chemicals (22). Section 710.7 of these regulations indicates that EPA intends to rely on powder diffraction data to assure the validity and seriousness of a manufacturers request for treating information on a chemical as confidential. 

G. NIOSH RTECS Search System. The National Institute for Occupational Safety and Health (NIOSH), created in 1970, is required by law to prepare a list containing all the toxic effects of chemicals that can be found to have been recorded (24). The Registry of Toxic Effects of Chemical Substances (RTECS) is the data base created and updated annually by NIOSH to fulfill the provisions of this law. In 1977 the data base consisted of some 25,000 chemicals and the toxicity associated with these chemicals. 

I. X-Ray Literature Search System. The data base used in the X-ray crystallographic search system described in (c) above possesses complete literature references to all entries in the file [4], This information has been made the basis of a system for searching by author, title word, etc, the literature pertaining to the X-ray diffraction study of organic molecules. 

J. Proton Affinity Retrieval Prograno. With the current high level of interest in chemical ionization mass spectrometry, there is a need for a reliable file of gas phase proton affinities. No data base of this sort has previously been assembled and for these reasons, the task of gathering and evaluating all published gas phase proton affinities has been undertaken by Rosenstock and co-workers at NBS. This file [28], which has about 400 critically evaluated gas phase proton affinities drawn from the open literature, and can be searched on the basis of compound type or the proton affinity value. It will be appended to the MSSS and the bibliographic component will be merged with the Mass Spectrometry Bulletin Search System. 

Algorithm development in the areas of computer editing, data base management, sorting, computer-based composition, and text searching have been critical to the overall development of computer-based primary and secondary publications systems and text search services. Results of these developments are illustrated in the computer-based information system used at Chemical Abstracts Service (CAS) [ 1]. Lynch [2J describes principles and techniques for the computer-based information services and... 

In an effort to avoid reproducing indexing errors from other systems, hard copy of all articles selected for inclusion into the data base is always obtained before information is entered into the ETIC file. When a complete copy of an article is in hand, the bibliographic data are entered into the computer. The fields that are entered include the author, title, citation, literature type, language or translation notes, secondary source, and selected abstracts. The technical staff then indexes the data using experimental parameters that allow searching in a variety of ways specific to the interests of the users. Only that portion of the paper concerned with teratology or... 

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